> If the client sleeps for a few ms at each loop, the success rate > increases. At 15 ms, the script always succeeds so far. Interestingly, > the problem seems to be sensitive to alphabetical order. Updating the > value from 'aaa' to 'bbb' never has problem. No pause needed.
Is it possible the version of pycassa you're using does not guarantee that successive queries use non-identical and monotonically increasing timestamps? I'm just speculating, but if that is the case and two requests are sent with the same timestamp (due to resolution being lower than the time it takes between calls), the tie breaking would be the column value which jives with the fact that you're saying it seems to depend on the value. (I haven't checked current nor past versions of pycassa to determine if this is plausible. Just speculating.) -- / Peter Schuller (@scode on twitter)
